title: Increased pressure pain sensitivity in women with chronic pelvic pain.
abstract: OBJECTIVE
  To determine whether women with chronic pelvic pain and variable degrees of endometriosis demonstrate altered pain sensitivity relative to pain-free healthy women in a control group and whether such differences are related to the presence or severity of endometriosis or comorbid pain syndromes.
  
  
  METHODS
  Four patient subgroups (endometriosis with chronic pelvic pain [n=42], endometriosis with dysmenorrhea [n=15], pain-free endometriosis [n=35], and chronic pelvic pain without endometriosis [n=22]) were each compared with 30 healthy women in a control group in this cross-sectional study. All patients completed validated questionnaires regarding pain symptoms and underwent screening for comorbid pain disorders. Pain sensitivity was assessed by applying discrete pressure stimuli to the thumbnail using a previously validated protocol.
  
  
  RESULTS
  While adjusting for age and education, pain thresholds were lower in all subgroups of women with pelvic pain relative to healthy women in the control group (all P values <.01). There was no difference in pain thresholds when comparing patients with endometriosis without pelvic pain with healthy women in the control group (mean difference 0.02 kg/m2, 95% confidence interval -0.43 to 0.47). The presence and severity of endometriosis and number of comorbid pain syndromes were not associated with a difference in pain thresholds.
  
  
  CONCLUSIONS
  Women with chronic pelvic pain demonstrate increased pain sensitivity at a nonpelvic site compared with healthy women in a control group, which is independent of the presence or severity of endometriosis or comorbid pain syndromes. These findings support the notion that central pain amplification may play a role in the development of pelvic pain and may explain why some women with pelvic pain do not respond to therapies aimed at eliminating endometriosis lesions.
  
  
  METHODS
  II.
authors.affiliation: Departments of Obstetrics and Gynecology, Anesthesiology, and Internal Medicine (Rheumatology), University of Michigan Health Center, Ann Arbor, Michigan; and the Department of Obstetrics and Gynecology, Northshore University Health System, Chicago, Illinois.
authors.forename: Sawsan
authors.initials: S
authors.lastname: As-Sanie
authors.forename: Richard E
authors.initials: RE
authors.lastname: Harris
authors.forename: Steven E
authors.initials: SE
authors.lastname: Harte
authors.forename: Frank F
authors.initials: FF
authors.lastname: Tu
authors.forename: Gina
authors.initials: G
authors.lastname: Neshewat
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Clauw
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D059350:Chronic Pain / Q000150:complications / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004412:Dysmenorrhea / Q000150:complications / Q000503:physiopathology; D004715:Endometriosis / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D017699:Pelvic Pain / Q000150:complications / Q000503:physiopathology*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult